Intra prediction based on transform domain equation

Abstract

The various implementations described herein include methods and systems for coding video. In one aspect, a method includes receiving a video bitstream comprising a plurality of blocks. The plurality of blocks includes a current block. The method includes obtaining an intra prediction for the current block. The method includes generating a refined intra prediction by applying a transform-domain equation to the intra prediction. The method also includes reconstructing the current block using the refined intra prediction.

What is claimed is: 
     
         1 . A method of video decoding performed at a computing system having memory and one or more processors, the method comprising:
 receiving a video bitstream comprising a plurality of blocks, including a current block;   obtaining an intra prediction for the current block;   generating a refined intra prediction by applying a transform-domain equation to the intra prediction; and   reconstructing the current block using the refined intra prediction.   
     
     
         2 . The method of  claim 1 , wherein the refined intra prediction is generated using a set of known samples adjacent to the current block. 
     
     
         3 . The method of  claim 2 , wherein applying the transform-domain equation comprises refining T(P) such that T(P)*T(W) approaches T(P·W), wherein T is a transform function, P corresponds to the intra prediction, and W is a window function. 
     
     
         4 . The method of  claim 3 , wherein W has a shape corresponding to the set of known samples. 
     
     
         5 . The method of  claim 3 , wherein W has a shape corresponding to the set of known samples and encompassing at least a portion of the current block. 
     
     
         6 . The method of  claim 3 , wherein W includes a gradient section along a boundary of the window function. 
     
     
         7 . The method of  claim 6 , wherein the boundary is an L-shaped boundary. 
     
     
         8 . The method of  claim 6 , wherein the boundary is a curved boundary. 
     
     
         9 . The method of  claim 3 , wherein P corresponds to a region that is larger than a size of the current block. 
     
     
         10 . The method of  claim 1 , wherein the transform-domain equation is applied with one or more constraints. 
     
     
         11 . The method of  claim 10 , wherein the one or more constraints comprise a distortion constraint for one or more known samples. 
     
     
         12 . The method of  claim 10 , wherein the one or more constraints comprise a directionality constraint. 
     
     
         13 . The method of  claim 1 , wherein the intra prediction is obtained using one or more transform-domain techniques. 
     
     
         14 . A method of video encoding performed at a computing system having memory and one or more processors, the method comprising:
 receiving video data comprising a plurality of blocks, including a current block;   obtaining an intra prediction for the current block;   generating a refined intra prediction by applying a transform-domain equation to the intra prediction; and   encoding the current block using the refined intra prediction.   
     
     
         15 . The method of  claim 14 , wherein the refined intra prediction is generated using a set of known samples adjacent to the current block. 
     
     
         16 . The method of  claim 14 , wherein applying the transform-domain equation comprises refining T(P) such that T(P)*T(W) approaches T(P·W), wherein T is a transform function, P corresponds to the intra prediction, and W is a window function. 
     
     
         17 . The method of  claim 16 , wherein W includes a gradient section along a boundary of the window function. 
     
     
         18 . A non-transitory computer-readable storage medium storing a video bitstream that is generated by a video encoding method, the video encoding method comprising:
 receiving video data comprising a plurality of blocks, including a current block;   obtaining an intra prediction for the current block;   generating a refined intra prediction by applying a transform-domain equation to the intra prediction; and   encoding the current block using the refined intra prediction.   
     
     
         19 . The non-transitory computer-readable storage medium of  claim 18 , wherein the refined intra prediction is generated using a set of known samples adjacent to the current block. 
     
     
         20 . The non-transitory computer-readable storage medium of  claim 18 , wherein applying the transform-domain equation comprises refining T(P) such that T(P)*T(W) approaches T(P·W), wherein T is a transform function, P corresponds to the intra prediction, and W is a window function.